9 research outputs found

    Universal Design of ICT: A Historical Journey from Specialized Adaptations Towards Designing for Diversity

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    Over the last decades, the field of computer science has moved from specialized adaptations and add-on assistive technologies, toward universal solutions catering to a diverse set of user needs. Two paradigm shifts have arguably occurred on this journey: 1) a shift in disability perspective (from a medical model to a psychosocial and situated model) and 2) a shift from reactive accessibility efforts to proactive inclusive design efforts. In addition, we have changed our perception of the end-user (from ‘Mr. Average’ to situated individuals), have expanded our disciplinary epistemologies (from positivist objective knowledge to critical and empathic qualitative insights), and changed the way we build digital solutions (from plan-based with little user contact to iterative with high user contact). This article tells the story of this journey, and how these shifts have all influenced the way we think today. We argue that different ways of thinking about and arguing for universal design today are not necessary confrontations – but can be seen as evolvements over time to complement the different societal systems in which we are designing

    Endosperm development : dynamic processes and cellular innovations underlying sibling altruism

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    The endosperm is a product of fertilization that evolved to support and nourish its genetic twin sibling embryo. Cereal endosperm accumulates starch and protein stores, which later support the germinating seedling. These nutritional stores prompted the domestication of cereals and are the focus of ongoing efforts for crop improvement and biotechnological innovations. Endosperm development entails several novel modifications to basic cellular and developmental processes. Cereals display nuclear endosperm development, which begins with a period of free nuclear division to generate a coenocyte. Cytoskeletal arrays distribute nuclei around the periphery of the cytoplasm and direct the subsequent deposition of cell wall material during cellularization. Positional cues and signaling systems function dynamically in the specification of the four major cell types: transfer cells, embryo-surrounding cells, starchy endosperm (SE), and aleurone. Genome balance, epigenetic gene regulation, and parent-of-origin effects are essential for directing these processes. Transfer cells transport solutes, including sugars and amino acids, from the maternal plant tissues into the developing grain where they are partitioned between embryo and SE cells. Cells of the embryo-surrounding region appear to coordinate development of the embryo and endosperm. As the seed matures, SE cells assimilate starch and protein stores, undergo DNA endoreduplication, and finally undergo programmed cell death. In contrast, aleurone cells follow a maturation program similar to the embryo, allowing them to survive desiccation. At germination, the aleurone cells secrete amylases and proteases that hydrolyze the storage products of the SE to nourish the germinating seedlin

    A systematic review of the physical and chemical characteristics of pollutants from biomass burning and combustion of fossil fuels and health effects in Brazil

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    The aim of this study was to carry out a review of scientific literature published in Brazil between 2000 and 2009 on the characteristics of air pollutants from different emission sources, especially particulate matter (PM) and its effects on respiratory health. Using electronic databases, a systematic literature review was performed of all research related to air pollutant emissions. Publications were analyzed to identify the physical and chemical characteristics of pollutants from different emission sources and their related effects on the respiratory system. The PM2.5 is composed predominantly of organic compounds with 20% of inorganic elements. Higher concentrations of metals were detected in metropolitan areas than in biomass burning regions. The relative risk of hospital admissions due to respiratory diseases in children was higher than in the elderly population. The results of studies of health effects of air pollution are specific to the region where the emissions occurred and should not be used to depict the situation in other areas with different emission sources

    Biological and synthetic template-directed syntheses of mineralized hybrid and inorganic materials

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    Systemlehre und Pflanzengeographie

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